Unbelievable Machine Double...I think

I have never seen such an example.

 

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Nope.

 

That's die deterioration doubling.

 

I am

Oh, thank you. It's hard to tell the difference for me still. It's pretty cool looking even if it is not valuable.

 

Ahhhhh! Still learning. Thank you though

 

We all are.

 

While die deterioration doubling is a possiblity, it's more likely a case of plating disturbance doubling.

 

Exactly. When it took the hop it threw off the plating. Look at the bubbly surfaces and see the plating issues on the planchet well before the dies were even there. Those dies weren't deteriorated, the planchet was already in trouble.

 

Please explain this (PDW) and how it occurred. It appears the the plating is intact and not "thrown off" an one member says.

 

It double-struck in those areas over plating that was already compromised. Geeze, this isn't rocket science.

 

Are you writing that the cent was double struck in the collar?

 

It's strike-doubling. That's how it shows on these planchets, it takes up the loose plating.

 

It has nothing to do with strike doubling (machine doubling). The increased tensile stresses located at the edge of the design causes the plating to lift away from the underlying zinc core. I like to compare it to the blister caused by a severe Indian burn. In other cents, the plating just splits (split plating doubling). The same mechanism generates both effects.

 

There is no such phenomenon as "pull away" and I have never used the term. Split plating doubling and plating disturbance doubling can be localized.

 

You must pay better attention. Mike called it "lift away." I called it "takes up." We're speaking the same language. I credit it to the impact of the strike, and I'm sure Mike agrees. He has a better description of it, however, a description specific to these plated planchets, differentiating it from what we're accustomed to calling "strike-doubling."

 

I must emphasize that nothing is lifting up the plating from the outside. It has simply lost its bond to the zinc core. It's possible that expanding gas from the heat of the strike is pushing up the plating, like a plating blister, but I can't be sure.

 

Is the effect of "split plating" where the shiny zinc core shows next to the copper plating that has "pulled-away" from the relief?

If so, that is NOT the same as a plated surface being bubbled as the die "pulls away" from the struck coin. I'm not understanding something here if you wish to continue my education and that of others here.

 

No, the split plating does not lift up. However, both phenomena are associated with the areas where tensile stresses tend to concentrate.

 

Yhanks for all the info!

What causes SIDEWAYS split plating?

What causes Pulled-up split plating as it appears on the OP's coin?